In one common configuration, known in the prior art, corn heads comprise a laterally extending frame to which many row units are attached. The frame is configured to be supported on the front of an agricultural combine. Each row unit is configured to engage an individual row of crop plants, cutting the crop plant from the ground, and stripping the crop from the corn stalk. In one common row unit configuration, the row unit grasps the cornstalk, pulls it downward, and pulls the ears of corn off the stalk. These ears of corn are then provided to the threshing, separating, and cleaning portions of the agricultural combine to remove the individual kernels of corn. These kernels of corn are saved in a grain tank in the harvester.
Row units for corn heads typically have two forwardly extending rolls called “stalk rolls” that are disposed adjacent to each other. The stalk rolls are driven in rotation such that corn stalks trapped between them are pulled downward and ejected into the dirt below the corn head while the ears of corn are stripped off the stalk.
One problem with the row units for corn heads is their susceptibility to being jammed with shreds of plant matter, corn kernels, dirt, grass, or other materials on the ground. The row units skid along the ground, permitting all manner of contaminants to be introduced into the row unit.
A typical stalk roll may rotate at 1000 rpm as it travels along the ground only a few inches away from the dirt. Grass, weeds, broken corn stalks or other material may become jammed between the spinning stalk roll and the row unit gearbox on which it is mounted.
One solution to this problem has been to locate the stalk roll very closely to the gearbox itself providing a very small gap therebetween. Nonetheless, long fibrous plant material can become wrapped around the base of the stalk roll and wedged into this gap.
What is needed, therefore, is a row unit with an improved row unit gear box and stalk roll that reduced the likelihood of contamination. It is an object of this invention to provide such a row unit and stalk rolls.